the best possible way would be to make the gfwl login optional, not mandatory. and logging in and out of gfwl should not affect your save game. it should not feel intrusive. in fact, logging in should just be a click of the mouse if anything at all. games should be playable as they install, always be prepared to avoid server issues, and make it available offline. a huge plus would be the ability to somehow connect your steam library to it. in fact, that would be a massive plus.